Friction/acceleration of cylinder

[fw029]

Homework Statement

given a situation (http://teachingphysics.files.wordpress.com/2009/03/spool-21.png" ) where a string with tension is pulling a spool of mass m from the bottom, what would be the directions of acceleration and friction? note: there's no slip at all.

given: tension equals weight (mg). the spool has rotational inertia I=(1/2)mr^2

Homework Equations

(not trying to calculate anything)

The Attempt at a Solution

the spool would wind up, so velocity would be to the right I think. if you make the axis at where it touches the ground, tension is the only force providing torque...so I think angular acceleration would be clockwise, and so linear acceleration would be pointing right, and friction would be towards the left?

I'm not really sure, so any help would be appreciated.

 

[Delphi51]

Welcome to PF.
It sure looks to me like pulling the string will try to unwind the spool and make it turn counterclockwise so it will try to go left. Friction will give it a grip on the table. You'll have a left force AND a right force which will have to be calculated to see which way it goes. It may well go right and wind the string if the friction is sufficiently strong.

 

[ashishsinghal]

hint: since there is no slip acceleration at point of contact is zero